Another job that was recently "repaired" but now having issues. The pivot shaft is leaking a lot on RH side and a bit less on the other side ; both while machine is operating and while standing idle. We are using as recommended 50 weight oil. This job was repaired by an earlier mechanic, and he replaced the bushes ( in the main chassis) on both sides as well as the seals on both sides. Almost started leaking a little from the start, we hoped it might take up but it has not. We have lock-tightened all the flange bolts in case there was oil leaking along the threads but it now looks like we might have to pull off the track frames and start the whole job again. Apparently the pivot shaft showed some wear in the bush area when reassembled, but not where the seal sits and wear was deemed not enough in any case to require replacement shaft or metal spraying. Is there anything else we should try to seal it before we go ahead and fully dismantle the undercarriage? thanks again for you help.
What type of seal does it have ? One with steel rings inner dia and outer dia. or the parralellagram sectioned ones ? The ones with steel rings need to be indexed on installation so the frame can move through it's travel and not tear the rubber. The other type need the backing washer positioned to compress the rubber seal. Later Bob
Ill check this out in the morning and get back to you Bob, thanks.
...I recently had to have pivot shafts repaired on both sides cost 1000 ea and after we got them back older mechanic I was talking to tolded me he fills them with grease now and lil oil never had problem ..
Very tempting option thanks; I would like to see what anyone else thinks about the grease option or using a very heavy grade oil as an alternative to the 50W?
Yes me too I have 2 running now d5m and d6h all broke down same time see post of the d6h I have ...older cat tech was who I was talking to
I think they should repaired properly and have 50w in them. Unless you are unlucky and get a sharp rock jammed in there which punctures the seal, they are very reliable.
The only thing heavier than SAE50 (it's not 50W, there's no such thing) is SAE60. If you are thinking EP gear oil because the numbers are higher then an 80W/90 is about equivalent to an SAE50 in viscosity and an 85W/140 about equivalent to an SAE60 - so no real benefit there. I've heard the stories about using grease but to be honest all we used to do with leaking pivot shaft seals was keep pouring SAE50 into them until we could get the tractor to the shop, pull everything apart and fix the seals properly. As CMark pointed out these seals are generally very reliable and if they leak it often points to another underlying issue that can be a very expensive fix. Therefore a leaking pivot shaft seal generally warrants fixing sooner rather than later or it'll cost you a minimum of a new shaft and a pair of frame bushes (US$13,000-ish for the 3 items) even if it's the day you won the lottery.
True but Grease will work ...I hate to debate with people who have more years in heavy equipment and have helped me learn earth moving equipment but long ago loggers started running grease in log trailer hubs simply because if plastic or alumuim hubs cracked and 90 w 140 would leak causing bearing to over heat and lockup and axle replacement or fire and etc ..I know dozer don't use light seals hell I just redid a d6h and had a bunch of machine work done because no oil in pivot shafts . But now most all trailers have options oil or grease plus they carry 20 to 30 tons with a full rotation around spindle yes they are preloaded bearings verse solid bearings but its still lubed and doesn't leak out as easy ...Just saying a easy fix aint always right but this seems to make sense and would work ...If im wrong ill be the first to say I am ...Im running grease oil mix in 2 dozers and need to check our other 2 to see if oil has leaked out when they get near shop ...Guys remember im running a shop that had no mechanic for 3 years and 30 machines most are cats ...
You're not debating at all. You're expressing your thoughts on what works for you in your particular situation and from your text you're having to play some serious catch-up and prioritize what needs done to the resources you have available to do it. Nothing wrong with that. The issue as I see it with pivot shafts on larger tractors (remember we're talking a D8 here as opposed to the D5/D6 you're working on) is that experience has shown me that if one pivot shaft seal is leaking you may have a seal issue, if they are both leaking the issue is 90% or more guaranteed to be much deeper that that. The longer you leave it the more money it costs to fix it right when you do finally pull it apart. The tractor to which the OP refers has had new frame bushes and new seals installed but still leaks. My bet would be that the pivot shaft itself is worn.
We are hoping to have a good look at this leak next week; Ill let you know what we come up with. I really appreciate everyone's comments, thank you.
As an outside bet if the seals were replaced recently and someone oriented the new seals incorrectly on the track frame then they would have to be strained in order to get the bolts in which would tear up the new seals in quick time.